This washable cotton face mask is lined with a three-layer SMS 600 polypropylene sterilization wrap. Exterior layer is quilters cotton fabric. There is a bias tape channel for a removable nose wire (included) and side channels for elastic ear loops.
This material is machine washable and able to withstand the autoclave process.
Medium, and Large masks are made with 8.5" elastic loops, which can be tied tighter if needed. XS and Small masks are made with 6.5 elastic loops.
Information on this material and it's uses in masks can be found here: